Sarla Goel

Preparation and 31P NMR studies of cationic methyl platinum(II) complexes containing mixed ligands

Abstract The preparation of some new cationic methylplatinum(II) complexes containing mixed ligands of general formula, [PtMe( LL )(L′)]+PF−6 1 [ LL =Ph2PC2H4PPh2 and L′ = Ph2MeP, Ph3As and (p-YC6H4)3P; Y = F, H, CH3, CH3O, (CH3)2N] and [PtMe( LL′ (L″)]+PF−6, 2 [ LL′ =Ph2PC2H4AsPh2 and L″ = (PhO)3P and (p-YC6H4)3P; Y = F, CH3, CH3O] has been described. The 31P NMR spectra of complexes 1 and 2 consisting of 36 and 12 lines respectively are discussed. the trans-effect of the para-substituted phosphines has been related to their electronic parameters by measuring the platinumphosphorous coupling constants (JPt-P) which follows the trend F

Synthesis and NMR Spectral Studies of Mixed Phosphine Platinum(II) Complexes

Abstract Mixed phosphine platinum (II) complexes of the type trans-PtC1 (P-C)L [where (P-C) = But 2 PCMe2CH2 and L = (p-YC6H4)3 P; Y = Cl, F, H, CH3, CH3O and (CH3)2N] have been synthesized by the bridge-splitting reactions of chloro-bridged dinuclear platinum(II) complex, [PtCl(P-C)]2, with para-substituted triphenyl phosphines. On the basis of the 12 line 31P NMR spectra which show large phosphorus-phosphorus coupling constants (JP-P′ ≈ 420 Hz), trans-configuration has been assigned. The trans-effect of the para-substituted phosphines has been related to their electronic parameters by measuring the platinum-phosphorus coupling constants (JPt-P) which follows the trend Cl < F < H < CH3 < CH3O < (CH3)2N.

Formation of unusual palladium(II) complexes containing metalated tri-t-butylphosphine and bidentate ligands

Abstract The bridge-splitting reactions of chloro-bridged dinuclear palladium(II) complex containing metalated tri-t-butylphosphine, [Pd(μ-Cl)(P-C)]2 (1) (P-C = Bu2tPCMe2CH2), with four types of bidentate ligands, [ L L = Ph2PCH2PPh2(dpm), Ph2AsC2H4PPh2(ape), (bipy)], have been shown to produce [P-C)ClPd(dpm)PdCl(P-C)] (2), [(P-C)ClPd(ape)] (3), [(P-C)ClPd(diars)] (4) and [(P-C)ClPd(bipy)] (5). Complex (3) has been found to exist in solution as an equilibrium mixture of a neutral four coordinate palladium(II) complex with ‘arphos’ acting as a monodentate ligand, [( P-C)Pd Cl(PPh2C2H4AsPh2)] and a cationic complex, [( P-C)P d(PPh 2 C 2 H 4 A sPh2)]+Cl−. ‘Diars’ and bipyridyl ligands have been found to behave as mono-dentate ligands, incapable of replacing the chloride ligand to yield the corresponding cationic complexes. Stable cationic complexes, [( P-C)P d(L-L ′)]+PF6− have been prepared from the reaction of AgPF6 with complex 1 followed by the addition of the bidentate ligand.

Synthesis and characterization of trichlorostannyl—platinum(II) complexes containing a platinum—carbon bond and mixed ligands

Abstract Several trichlorostannyl—platinum(II) complexes containing platinum—carbon bond and mixed ligands, trans -[PtSnCl 3 (PC)L] (1) [where (PC) = Bu 2 t PCMe 2 CH 2 and L = Ph 3 As, Ph 3 Sb, CO, PCy 3 , PBu 2 t R, PPh 2 Me, P(C 6 H 4 Y) 3 (Y = Cl, F, H, CH 3 , OCH 3 ) have been prepared by the reaction of tin(II) chloride with the corresponding chloro—platinum(II) complexes, trans -[PtCl(PC)L] (2). Complexes 1 have been characterized by their elemental analysis, 1 H and 31 P NMR spectral data. 31 P NMR spectra of these complexes show complex patterns with platinum—phosphorus and tin—phosphorus couplings. The trans -configuration has been assigned to these complexes containing mixed phosphine ligands on the basis of 31 P NMR spectra which show large phosphorus—phosphorus coupling constants ( 2 J(PP′) ∼ 307–339 Hz). The trans -effect of the para -substituted phosphines has been related to their electronic parameters by measuring the platinum—phosphorus coupling constants (J PtP) of the metalated phosphine present at the trans position which follows the trend Cl 3 3 O.

Chemistry of metal-diene complexes; a direct, new preparative route to hydrido-platinum(II) complexes

A new preparative route to hydrido-platinum(II) complexes, particularly those containing bulky phosphines which are inaccessible by other methods, involves the convenient reaction of phosphines with bis [(2-methoxy-5-cyclooctenyl)chloroplatinum] in methanol. A β-hydrogen elimination mechanism is described, as well as the preparation and use as hydrogenation catalysts of the complexes trans-[(2-CH3O-5-C8H12)Pt(L)Cl] where L = tertiary phosphine

Chemistry of mixed ligand complexes of platinum: crystal and molecular structure of trans-[PtCl(CH3)(PEt3)(AsPh3)]

Abstract The dimethyl platinum(II) complex containing mixed ligands, cis -[Pt(CH 3 ) 2 (PEt 3 )(AsPh 3 )] reacted with one equivalent of hydrogen chloride yielding trans -[PtCl(CH 3 )(PEt 3 )(AsPh 3 )]. The X-ray crystal structure of the molecule shows the trans orientation of the PEt 3 and AsPh 3 ligands.

Synthesis and characterization of hydrido-platinum(II) complexes containing mixed phosphine ligands

Abstract Several hydrido-platinum(II) complexes containing two non-equivalent phosphine ligands, [PtH(PC)(PR3)] (2) [where (PC) = But2PCMe2tCH2 and PR3 = PEt3, PPhi3, PBut2ME, PBu3, P(C[6H4-Me)3, P(OPh)3] have been prepared by the reaction sodium borohydride with the corresponding chloro-platinum(II) complexes, [PtCl(PC)(PR3)] (1). A trinuclear platinum cluster, [Pt(CO)(PBut3)]3, has been isolated from a similar reaction of sodium borohydride with [PtCl(PC)(CO)]. Complexes 2 have been characterized by their elemental analysis, infrared, 1H NMR and 31P NMR spectral data. The trans-configuration has been assigned to these complexes on the basis of a 12 line 31P NMR spectra which shows large phosphorus-phosphorus coupling constants(2J(PP′) = 371–400 Hz). The trans-effect of the alkyl phosphines has been related to their steric parameters by measuring the platinum-phosphorus coupling constants (1J(PtP)) of the metallated phosphine present at the trans-position.